Archive weekly and monthly coal production — revised and original estimates

About coal production revision estimates

EIA revises its weekly
(and monthly) original estimates of state level coal production using quarterly mine level coal production
data from the Mine Safety and Health Administration
(MSHA) as soon as the data are available. This method guarantees that EIA's revised coal
production estimates for each past quarter conform with the MSHA survey
data. The state level revised estimates include refuse coal.

EIA uses this equation to revise its weekly coal production estimates:

Revised weekly estimate (state A) =
MSHA quarterly data (state A) x Total number of U.S. railcar loadings of coal in a week ÷
Total number of U.S. railcar loadings of coal for all weeks in a quarter

Note: All weeks reported in the tables
end on a Saturday. The estimates for the first and last weeks in a year include
estimated coal production only for the days that occurred in the year.